This invention is directed to the field of spray dispensers. The invention is particularly directed to trigger dispensers, also known as trigger sprayers, having structure for drawing and mixing fluid from containers having more than one compartment.
There are numerous issued patents concerning trigger sprayers capable of dispensing liquid from single compartment containers. Generally, these trigger sprayers are relatively low-cost hand-held pump devices having triggers. The sprayers may be grasped in the hand and the trigger may be pulled to pump liquid from the container and through a nozzle orifice at the front of the sprayer. Typically, trigger sprayers have a dip tube extending from the bottom of the container interior to the trigger sprayer housing so liquid may be drawn from the container. Some type of pump is generally included in the sprayers. These pumps have expandable chambers which draw liquid from the containers as they expand and expel the liquid through the nozzle orifices as they contract. These trigger sprayers also typically have check valves positioned between the dip tube and pump and between the pump and nozzle orifice to assure liquid flows in the appropriate direction through the sprayer. Many of the trigger sprayers also have vent systems to prevent a vacuum from building within the container when liquid is withdrawn. A vacuum will eventually prevent liquid from being dispensed from the sprayer.
Single compartment trigger sprayers work well for most products, however some products have a limited shelf life due to interaction between the components of the product. This highlights a drawback inherent with single compartment trigger sprayers. The various components of the product must be mixed while in the single compartment container which may cause a shortened shelf life. For these products the use of a single compartment container requires that the product be mixed shortly before dispensing. As a result, only small batches of product may be mixed at a time which is an inconvenience.
In addition, some products will not mix together. For instance, if oil and water were placed in a container having a single compartment, the components would separate over time. Since the typical trigger sprayer has a dip tube which extends to the bottom of the container, the component at the bottom of the container will be dispensed first and when that supply is exhausted the second component will then be dispensed. Thus, the consumer must shake the container just before dispensing to achieve a mixture of components of the product. Consumers, however, frequently neglect to shake dispensers before using them thereby producing unsatisfactory results if the components have separated.
Still another problem inherent with the single compartment sprayers is evident under the following circumstances. Sometimes, a concentrated mixture is used in conjunction with a dilutant, frequently water. Depending upon the application, various concentrations are desired. With a single compartment container trigger sprayer apparatus, concentration variations are only available by remixing the contents of the container. This remixing causes waste and inconvenience for the consumer.
Thus, several multiple compartment trigger sprayers have been invented. For instance, U.S. Pat. No. 5,152,431 of Gardner et al. discloses a trigger sprayer with a multiple compartmented container. A separate dip tube extends into each of the compartments and the sprayer is rotatable so that it can alternately be aligned with any one of the dip tubes at a time. Thus, different products are available depending upon which dip tube is selected. However, variable mixture ratios of the products are not available. Also, it is not possible to simultaneously dispense two components without premixing them.
U.S. Pat. No. 4,355,739 of Vierkotter discloses a dual compartment liquid storage container which may be attached to a typical single dip tube sprayer apparatus to form a trigger sprayer capable of segregated product storage. However, because there are no check valves in the system between the mixing chamber and dip tubes, the container may permit cross-mixing of the components and reintroduction of the mixed components into the container compartments.
U.S. Pat. No. 5,009,342 of Lawrence et al. discloses a device similar to the Vierkotter device.